The Illini (8-3) jumped out to a 27-11 lead early in the first half, but Hampton (4-6) made a run behind leading scorer Quinton Chievous. The senior scored eight consecutive points on a 10-0 Hampton run.
Illinois closed out the half on a strong note when Nunn drilled a buzzer-beating 3-pointer to push the lead back up to 12.
After missing his first two shots, Nunn made his next six, including four 3-pointers.
In the second half, the lead wouldn't dip into single digits as the Illini stifled the Pirates.
Deron Powers and Dwight Meikle led Hampton with 12 points each, although the Pirates never led in the game.
Rayvonte Rice added 12 points and five rebounds for Illinois.
